Age-related abnormalities of oxidoreductase activity and mitochondria in rat hippocampal formation.

The activity of oxidoreductases in the hippocampal formation of young adult (3-month old) and aged (24-month old) Wistar rats was compared by histochemical methods. A decreased activity of NADH-diaphorase and dehydrogenases involved in the Krebs cycle and glycolysis as well as an increased activity of glucose-6-phosphate dehydrogenase were demonstrated in the hippocampal nerve cells of aged rats. The activity of oxidoreductases in the glial cells of aged rats was increased. Degenerative changes in scattered mitochondria were seen ultrastructurally. No significant differences in the relative volume fraction of mitochondria in the presynaptic axon terminals and dendrites were found between young adult and aged rats.